1. Field of the Invention
This invention relates to a process and a device for the removal of contaminants from gas generated by the gasification of fossil fuels and, more particularly, this invention relates to a method and device for removal of HCl with a regenerable sorbent and simultaneous extraction of hydrogen chloride compounds and hydrogen sulfide from fuel gas.
2. Background of the Invention
A large number of components in coal and other carbon-base fuels form corrosive and toxic compounds during the gasification processes. Treatment systems for removal of these contaminants utilize wet or dry scrubbing systems wherein compounds are added to remove these corrosive or toxic compounds. According to estimates, contaminants have to be reduced to parts per million (ppm) range and preferably in the parts per billion (ppb) range in order to utilize gasification gas streams in many applications. Even more stringent requirements are expected if the fuel gas is to be utilized in chemical production applications. Hydrogen chloride and hydrogen sulfide are two corrosive compounds that need to be removed from the coal gas streams. In order to provide an economical process as well as an environmentally friendly process from the perspective of waste products generated, it would be preferable to use a regenerable sorbent. There are no regenerable warm/hot gas clean up sorbents that can remove the hydrogen chloride levels at warm gas temperatures. There are disposable sorbents for HCl removal. Disposal problems associated with disposable sorbents can be eliminated by developing a regenerable sorbent. The coal gas could be utilized in many applications such as fuel cells and chemical co-production if the hydrogen chloride in the gases could be removed to below 1 ppmV range while meeting future environmental regulations. So the product from this project will benefit industry.
There are no regenerable sorbents reported in the literature for HCl removal at warm (200°-450° C.) or hot gas temperatures (>450° C.). The re are no multi functional sorbents reported in the literature to remove both H2S and HCl simultaneously. Utilization of a multi-functional sorbent to remove both H2S and HCl simultaneously will minimize the number of steps involved in the process and contribute to lower cost of operation.
A need exists in the art to provide a method and process for the removal of HCl and H2S resulting from gasification of coal simultaneously and reuse the material for multiple cycles.